Telephone system



H. 'P. CLAUSEN AND 0. L. GOODRUM.

TELEPHONE SYSTEM.

APPLICATION FILE!) DEC-28.19I8.

1,396,730. Patented Nov. 15, 1921.

venfa ms Hen r y/P C/fluwen Char/e a i. Quad/um UNITED. s'ra'ras PATENTOFFICE.

HENRY P. CLAUSEN, 0]! MOUNT VERNON, AND CHARLES I1. GOOIDRUM, OF NEWYORK,v

N. Y., .ASSIGNOBS TO WESTERN ELECTRIO COMPANY, INCORPORATED, OF NEWYORK, N. Y., A CORPORATION OF NEW YORK. 4

. TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Nov. 15, 1921.

Application filed December 28, 1818. 1 Serial No. 268,661.

To all whom it may concern:

Be it known-that we, HENRY P. CLAUSEN and CHARLES L. GOODRUM, citizensof the United States, residing at Mount Vernon, in the county ofWestchester and State of New York, and at New York, in the, county ofNew York and State of New" York, respectively, have invented certain newand useful Improvements in Telephone Systems, of which the following isa full, clear, concise, and exact description.

This invention relates to improvemehts in telephone exchange systems andhas particular reference to a circuit arrangement 'for controllingautomatic switches over long distance trunks.

In present practice, it is desirable that two wires forming a telephonecircuit be employed for other purposes, such as a path for controllingthe operation of automatic switches and for the transmission oftelegraph messages. Over trunk circuits extending between two widelyseparated points, it is difiicult, if not impracticable, tosimultaneously employ these circuits for all of the above-mentionedpurposes or for as many of them as may be desired under conditionsexisting in a given situation.

An object of the present invention is to provide an improved systemwhich may be simultaneously employed for all or any number of the aboverelated purposes. In accordance with this object, .a plurality oftelephone circuits may be provided with a common controllin circuithaving distributers at its two en s operating in synchronism, wherebythe setting of automatic switches at one end to connect a calling with acalled line may be controlled by impulses transmitted over the commoncontrolling circuit from the other end thereof. At the latter end of thecommon circuit one or more variably operable impulse controlling devicesare connected thereto and set in accordance with the desired number ofimpulses to be transmitted over said circuit. Means, preferably underthe control of an operator and associated with the synchronizeddistributers is operated to release the impulse controlling deviceswhereby the automatic switching mechanism is set to connect a callingwith a called line.

The inventive idea involved is capable of receiving a variety ofexpressions one of which, or the purpose of illlustrating the invention,is shown in the accompanying drawing; but it is to be expressslyunderstood that said drawing is employed merely for the urpose offacilitating the descript1on of t e invention, as a whole, and not todefine the limits thereof, reference being had to the appended claimsfor this purpose.

The drawlng illlustrates diagrammatically thecircuit arrangementemployed in carrying out the inventlon.

It is believed that the invention will be best understood from adetailed description of the operation in establishing a connectionreadily understood that as many of these:

circuits may be employed as is necessary to meet exlsting condltlons.The operator, upon belng lnformed of the wanted number,

will select an idle trunk circuit 1 and insert plug 2 thereof into jack3. A circuit is then closed from grounded battery, windin of 4, sleeveof plug 2, jack 3 and win ing rela of the usual sleeve relay 5, toground.

Relay 4, by attracting its right armature, establishes a circuit forrelay 6 extending from grounded battery, winding of relay 6, frontcontact and right armature of relay 4 to ground. Relay 6 energizes andcloses a lockin circuit for itself extending from grounded battery,winding of relay 6, right armature and front contact thereof, armatureand back contact of relay 7 to ground. By attracting its left armature,relay 4 breaks the circuit for release conductor 8 at the back contactof said armature and this circuit remains open until plug 2 is withdrawnfrom jack 3.

The operatorthen proceeds to set variably operable impulse controllingdevices, 'diagrammatically shown at 9 and 10, inaccordance with thedigits of the desired number.

One of these devices is provided for each series of impulses to betransmitted and the devices are arranged to operate successively. Whenthe dial of device 9 is operated, contact spring 11 engages contact 12and prepares a circuit for escape magnet 13 which, upon becomingenergized, releases controlling device 9 to permit of the transmissionof the desired number of impulses. As soon as the dial of the lastdevice 10 is operated, contact spring 14 associated therewith engagescontact 15 and likewise prepares a circuit for escape magnet 16 whichoperates to release controlling device 10 for the same purpose asdescribed in connection .with magnet 13. Contact spring 17 also engagesits associated contact, upon setting of the controlling device 10, andplaces ground upon the conductor 18. Several trunk lines, such as thetrunk 1, may be extended from the operators position B and associatedwith each line is a relay 19, two of which are shown for the purpose ofillustration. The lower armature of each relay 19 is connected to one ofthe terminals of a distributer 20, the wiper of which is connected to asimilar distributer 21 by a controlling circuit or conductor 22 which iscommon to the group of trunks. Thus, if an operator desires to extend acall on a second line While the first line is still in use, she setscontrolling devices 9 and 10 and depresses the key 26 associated withthe second line to operate its associated switch. Other distributers 23and 24 are also connected by a controlling circuit or conductor 25,common to said group of trunks over which the release of a talkingconnection is controlled, as will later appear. All of thesedistributers are preferably of a type such as employed in printingtelegraphy and are operated in synchronism by any means (not shown) wellknown in the art.

After setting devices 9 and 10 in accordance with the impulses to betransmitted, the v contact spring 17 to ground. Energization of relay 19closes a circuit, when the wipers of distributers 20 and 21 engage therespective terminals 27 and 28, which extends from grounded battery,left winding of relay 29 of the connector switch C, terminal 28,

. wiper of distributer 21, conductor 22, wiper of distributer 20,terminal 27, lower armature and front contact of relay 19, contactspring 11, contact 12 and winding of escape magnet 13 to ground. Magnet13 and relay 29 are simultaneously energized. The escapement mechanismof controlling device 9 is arranged in a manner well known in the art topermit the dial of said device to return toward its normal position uponthe release of said magnet which occurs when the wipers of thedistributers 20 and 21 disengage the terminals 27 and 28 at thetermination of each impulse. Thus upon each revolution of thedistributers an impulse for operating the switch C is transmitted overthe conductor 22. Energization of relay 29 establishes a locking circuitfor itself extending from grounded battery, armatures and back contactsof primary and secondary stepping magnets 31 and 42, front contact andinner armature of relay 29, and right winding of said relay to ground.By attracting its outer armature, relay 29 closes a circuit forslow-to-release relay 30 extending from grounded battery, winding ofrelay 30, front contact an outer armature of relay 29 to ground. Anothercircuit is simultaneously closed for primary magnet 31 extending fromgrounded battery, winding of said magnet, side switch wiper 32 inposition 1, front contact and outer armature of relay 29 to ground.Eneregization of magnet 31 breaks the locking circuit for relay 29 atthe back contact of said magnet and permits the armatures of said relayto release. Operation of said magnet 31 also steps brushes 33, 34 and 35of the connector switch 0 from their normal positions and closesoff-normal contact 36. Before the locking circuit for relay 29 isbroken, however, the wipers of distributers 20 and 21 will disengagetheir respective terminals 27 and 28 and interrupt the energizingcircuit for magnet 13 and relay 29. Upon the first energization ofescape magnet 13, a circuit is established for slow-to-release relay 37extending from grounded battery, winding of said relay, front contactand left armature of magnet 13 to ground; Relay 37 remains energizedduring the operation of controlling device 9. At the first energizationof relay 29, in addition to establishing the energizing circuits forrelay 30 and primary magnet 31, it also closes a circuit forslowto-release relay 38 extending from grounded battery, winding ofrelay 38, front contact and outer armature of relay 29 to ground. Relay38, in attracting its armature establishes a circuit for escape magnet39, extending from grounded battery, winding of magnet 39, side-switchwiper 40 in position 1, armature and front contact of relay 38 toground. The transmission of the first series of impulses for operatingmagnet 31 proceeds until the return of the dial of controlling device 9to its normal position at which time contact spring 11 is disengagedfrom contact 12 and moved into engagement with contact 41. The steppingcircuit for .magnet 13 and relay 29 is thereby broken and relay 37 afteran interval of time, de-

energizes. During this interval of time,

and the wipers of distributers 20 and 21 slow-to-release relays 30 and38 also release and upon deenergization of the latter, the ground isremoved for the energizing circult of escape ma et 39, which thenreleases and moves the side-switch wipers into position 2.

When slow-to-release relay 37 deenergizes again engage the respectiveterminals 27 and 28, a circuit will be closed for escape magnet 16associated with controlling device 10, and also for relay 29. Thiscircuit extends fromgrounded battery, left winding of relay 29, terminal28, wiper of distrlbuter 21, conductor 22, wiper ofdistributer 20,terminal 27, lower armature and front contact of relay 19, contactspring 11, contact 41, backcontact and armature of 'relay 37, contactspring 14, contact 15, and

winding of magnet 16 to ground. Operation of magn et 16 controls themovement of the dial of device 10 toward its normal position in the samemanner as described in connection with controlling device 9. Ener gzation of rela 29 again establishes the previously described lockingcircuit for itself and the circuits for slow-to-release relays'30 and38. Energi'zation of relay 38 again establishes a circuit for escapemagnet 39 through side switch wiper 40 in its second posltion. Upon thefirst ener ization of relay 29 a circuit is also closed fbr thesecdndary stepping magnet 42 extending from grounded battery, winding ofmagnet 42, side switch wiper 32 in position 2, .front contact and outerarmature of relay 29 to ground. Operation of secondary magnet 42 breaksthe locking circuit of relay 29 after the wipers of the distributers 20and 21 have passed over terminals 27 and 28, and relay 29 releases.Impulses continue to be transmitted to secondary stepping magnet 42 u neach revolution of the wipers of distributers 20 and 21, until thedialof controlling device 10 reaches its normal position and disengagescontact springs 14 and 17 from their associated contacts, whichoperation breaks the stepping circuit for magnet 16 and relay 29, andalso removes the holding ground for relay 19 which then deenergizes.Secondary magnet 42, in response to the second series of impulses, stepbrushes 33, 34 and, 35' onto the terminals 43, 44 and 45 of thetelephone line individual to substation apparatus D.

Assuming that the called substation D is busy, ground will be found upontest terminal 43 and upon de'e'nergization of slowto-release relay 30,at the termination of the second series of impulses, a circuit willbeclosed for release magnet 46 extending from grounded battery, leftwinding of magnet 46. back contact and armature of. relay 30,

side-switch wiper 47 in position 2, brush 33 and terminal 43 to ground.Release magnet 46 is energized and locked up over the circuit extendlnfrom grounded battery, right winding'of contact 36 to ground. Relay 38also deenergizes after. the termination of the second series of impulsesbut, being slow to release, sufficient interval of time will lapse topermit release magnet 46 to energize and thus establish another circuitfor escape magnet 39 which extends from grounded battery, winding ofmagnet 39, front contact and outer left armature of release magnet 46 toground. Therefore, escape magnet 39 will be unaffected by the release ofrelay 38 and consequent removal of ground from the armature thereof.Side-switch wipers of connector switch C will therefore be preventedfrom oving to position 3'. Energization of rele i se magnet 46 returnsswitch C to normal and .also applies a busy tone to the telephonecircuit which extends through the busy tone apparatus 48, front contactand inner left armature of release magnet- 46 to the upper side of thetelephone'circuit. The subscriber at substationA, hearing this busytone, replaces his receiver upon the switchhoo-k which operationextinguishes a supervisory lamp (not shown) at operators position B. Theoperator then removes plug 2 from jack 3 and thereby breaks the circuitfor relay 4, which then releases.

Should substation D be idle, slow-to-release relay 30 will becomedenergized at the termination of the second series of impulses and nopotential being found upon test terminal 43, release magnet 46 willremain deenergized. Relay 38 also releases and removes ground; at itsarmature from thecircuit of escape magnet 39 which deenergizes and movesthe side-switch wipers into position 3. Escape magnet 39 again energizesin position 3 over a circuit extending from grounded battery, winding ofmagnet 39, side-switch wiper 40 in position 3, armature and back contactof marginal relay 52 to ground. Ringing current isthen applied to theline over a circuit extending from ringing current generator 53, windingof relay 52, front contact and armature of escape magnet 39, side-switchwiper 53 in position'3, brush. 35, terminal 45, the ringer apparatus atsubstation D, terminal 44, brush 34 and side switch wiper 54 in position3 to ground. Sufficient current does not pass through marginal relay 52during the ringing operation to cause said relay to energize, but uponthe removal of the receiver at substation D, the ringer apparatusthereat is shunted and relay 52 becomes energized. Operation of relay 52removes ground from the armature thereof, and causes escape magnet 39 toagain release and move the sideswitch wipers into position 4. Talkingcurrent is now applied to the telephone line exmagnet 46, right armatureand front contact thereof, and oif-normal tending from grounded battery,right winding of relay 55, lower side of the telephone line, side-switchwiper 54 in position 4, brush 34, terminal 44, substation apparatus 1),terminal 45, brush 35, side-switch wiper 53 in position 4, and leftwinding of relay to ground. While side-switch wiper 4? is in eitherposition 3 or 4, a ground will be applied to test terminal 43 throughwiper 47 and brush 33 so that the line individual to substation D willtest busy to any other connector switch.

At the termination of the conversation, the subscriber at substation A,by replacing his receiver, extinguishes the supervisory lamp at theoperators position B as previously referred to. Removal of plug 2 fromjack 3, by the operator, breaks the circuit for relay 4, which thenreleases. As soon as the wipers of distributers 23 and 24 engageterminals 49 and 50, a circuit will be closed extending from groundedbattery, winding of relay 7, front contact and left armature ofslow-to-release relay 6, back contact and left armature of relay 4,conductor 8, terminal 49, wiper of distributer 23, conductor 25,

wiper of distributer 24, terminal 50 andleft winding of relay 51 toground. Relay 7 energizes and removes the holding circuit for relay 6,which in releasing interrupts the circuit for relay 7 to dee'nergizethis relay. Relay 51 is energized by the circuit just described andlocks up over the circuit extending from grounded battery, right windingof relay 51, inner armature and front contact thereof, and off-normalcontact 36 to ground. By attracting its outer armature, relay 51 placesround upon the conductor 56 and causes re ease magnet 46 to energizeover a circuit extending from grounded battery, left winding of magnet46,. conductor 56 and outer armature of relay 51 to ground. Releasemagnet 46 looks up over the previously desc-rlbed circuit through theoff-normal contact 36. -Energi'zation of release magnet 46 operates torestore switch C to normal position, whereupon off-normal contact 36 isopened and the switch is in position for another operation.

lVhat is claimed is:

1. In a telephone system, a plurality of trunk lines, a plurality ofswitches at which each trunk line terminates, a circuit independent ofand co-extensive with said trunk lines and means operating insynchronism for controlling any of said switches over said independentcircuit.

2. In a telephone system, calling and called lines, a plurality of linkcircuits, a controlling circuit common to said link circuits, means forconnecting any one of said calling lines with any link circuit,synchronously operable means for changing the electrical condition ofsaid controlling circuit and means responsive to certain of such saidindependent circuit to control the operation of said connecting means.

4. In a telephone system, calling and called lines, trunk linesfor'establishing connections between said calling and called lines, acircuit common to said trunk lines, switches for connecting said trunklines to said called lines, synchronously operable means fortransmitting impulses over said common circuit for operating saidswitches and means individual to each trunk line for causing the lastnamed means to operate one of said switches.

5. In a telephone system, a calling line, a called line, a plurality oftelephone circuits for establishing a connection between said callingand called lines, a controlling circuit common to said telephonecircuits, synchronized distributers for transmitting impulses over saidcontrolling circuit, and means responsive to the impulses transmittedfor connecting one of said telephone circuits to said called line.

6. In a telephone system, a calling line, a called line, a plurality oftelephone circuits for establishing a connection between said callingand called lines, a controlling circuit common to said telephonecircuits, synchronized distributers for transmitting impulses over saidcontrolling circuit, and an electrically operated switch controlled bysaid impulses for connecting one of said telephone circuits to saidcalled line.

7. In. a telephone system, a calling line, a called line, a plurality oftelephone circuits for establishing a connection between said callingand called lines, a controlling circuit common to saidtelephonecircuits, synchronized distributers connected to the ends of saidcontrolling circuit for transmitting impulses, successively operableimpulse controlling means associated with said synchronized distributersfor determining the number of impulses to be transmitted, and meansresponsive to the impulses transmitted for connecting one of saidtelephone circuits to said called line.

8. In a telephone system, a calling line, a called line, a plurality oftelephone circuits for establishing a connection between said callingand called lines, a controlling circuit independent of said telephonecircuits, synchronized distributers for transmitting impulses over .saidcontrolling circuit, and an electrically operated switch controlled bysaid impulses for connectin one of said telephone circuits to said caled line.

9. In a telephone system, a calling line, a called line; an operatorsposition, a plurality of circuits for establishing a connection betweensaid calling and called lines, a controlling circuit common to saidtelephone circuits, synchronized distributers for transmitting impulsesover said controlling circuit, means responsive to said impulses forconnecting one of said telephone circuits to said called line andsuccessively operable impulse controlling means at said. operatorsposition for determinin .the number of impulses to be transmitted.

10. In a telephone system, a calling line,

a called line, an operators position, a plurality of circuits forestablishing a connection between said calling and called lines, acontrolling circuit common to said telephone circuits, synchronizeddistributers for trans Initting impulses over said controlling circuit,means responsive to said impulses for connecting one of said telephonecircuits to said called line, and a relay for causing the operation ofsaid successively operable impulse controlling means,

In witness whereof, we hereunto subscribe our names this 12th day ofDecember, A. D.

HENRY P. CLAUSEN. CHARLES L. GOODRUM.

